target/s390x: rework PGM interrupt psw.addr handling

We can tell from the program interrupt code, whether a program interrupt
has to forward the address in the PGM new PSW
(suppressing/terminated/completed) to point at the next instruction, or
if it is nullifying and the PSW address does not have to be incremented.

So let's not modify the PSW address outside of the injection path and
handle this internally. We just have to handle instruction length
auto detection if no valid instruction length can be provided.

This should fix various program interrupt injection paths, where the
PSW was not properly forwarded.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170609142156.18767-3-david@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 35 insertions, 9 deletions

diff --git a/target/s390x/helper.c b/target/s390x/helper.c
index a8d20c51fa..aef09e1234 100644
--- a/target/s390x/helper.c
+++ b/target/s390x/helper.c
@@ -204,7 +204,7 @@ int s390_cpu_handle_mmu_fault(CPUState *cs, vaddr orig_vaddr,
     if (raddr > ram_size) {
         DPRINTF("%s: raddr %" PRIx64 " > ram_size %" PRIx64 "\n", __func__,
                 (uint64_t)raddr, (uint64_t)ram_size);
-        trigger_pgm_exception(env, PGM_ADDRESSING, ILEN_LATER_INC);
+        trigger_pgm_exception(env, PGM_ADDRESSING, ILEN_AUTO);
         return 1;
     }
 
@@ -331,16 +331,42 @@ static void do_program_interrupt(CPUS390XState *env)
     LowCore *lowcore;
     int ilen = env->int_pgm_ilen;
 
-    switch (ilen) {
-    case ILEN_LATER:
-        ilen = get_ilen(cpu_ldub_code(env, env->psw.addr));
-        break;
-    case ILEN_LATER_INC:
+    if (ilen == ILEN_AUTO) {
         ilen = get_ilen(cpu_ldub_code(env, env->psw.addr));
+    }
+    assert(ilen == 2 || ilen == 4 || ilen == 6);
+
+    switch (env->int_pgm_code) {
+    case PGM_PER:
+        if (env->per_perc_atmid & PER_CODE_EVENT_NULLIFICATION) {
+            break;
+        }
+        /* FALL THROUGH */
+    case PGM_OPERATION:
+    case PGM_PRIVILEGED:
+    case PGM_EXECUTE:
+    case PGM_PROTECTION:
+    case PGM_ADDRESSING:
+    case PGM_SPECIFICATION:
+    case PGM_DATA:
+    case PGM_FIXPT_OVERFLOW:
+    case PGM_FIXPT_DIVIDE:
+    case PGM_DEC_OVERFLOW:
+    case PGM_DEC_DIVIDE:
+    case PGM_HFP_EXP_OVERFLOW:
+    case PGM_HFP_EXP_UNDERFLOW:
+    case PGM_HFP_SIGNIFICANCE:
+    case PGM_HFP_DIVIDE:
+    case PGM_TRANS_SPEC:
+    case PGM_SPECIAL_OP:
+    case PGM_OPERAND:
+    case PGM_HFP_SQRT:
+    case PGM_PC_TRANS_SPEC:
+    case PGM_ALET_SPEC:
+    case PGM_MONITOR:
+        /* advance the PSW if our exception is not nullifying */
         env->psw.addr += ilen;
         break;
-    default:
-        assert(ilen == 2 || ilen == 4 || ilen == 6);
     }
 
     qemu_log_mask(CPU_LOG_INT, "%s: code=0x%x ilen=%d\n",
@@ -737,6 +763,6 @@ void s390x_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
     if (retaddr) {
         cpu_restore_state(cs, retaddr);
     }
-    program_interrupt(env, PGM_SPECIFICATION, ILEN_LATER);
+    program_interrupt(env, PGM_SPECIFICATION, ILEN_AUTO);
 }
 #endif /* CONFIG_USER_ONLY */